5) Calculate the molality of 0.210 mol of KBr dissolved in 0.075kg pure
water?

2.8 m

Explanation:

From the question given above, the following data were obtained:

Number of mole KBr = 0.210 mole

Mass of water = 0.075 kg

Molality of KBr =?

Molality is simply defined as the mole of solute per unit kg of water. Mathematically, it can be expressed as follow:

Molality = mole of solute / Kg of water.

With the above formula, we can obtain the molality of the KBr solution. This can be obtained as follow:

Number of mole KBr = 0.210 mole

Mass of water = 0.075 kg

Molality of KBr =?

Molality = mole of solute / Kg of water.

Molality = 0.210 / 0.075

Molality = 2.8 m

Therefore, the molality of the KBr solution is 2.8 m.

the answer is